A variety of can seaming apparatus are presently available for seaming lids onto metal cans in the food and beverage industries. Particularly for smaller cans with smaller lids, pneumatic sealing devices are preferable in terms of cost reduction and setup time. However, one existing difficulty in devices using air pressure to drive pivoting arms equipped with seam rollers into a can seaming area is in maintaining the high accuracy necessary to drive the roller into the correct position at the seaming area to produce a sufficient seam.
Typically, an air cylinder drives the seam roller into the seaming area. However, maintaining a consistent dimensional deformation throughout the seaming area is difficult to achieve with air cylinders in conventional designs. Existing methods use a sequence of two seam rollers to form the lips of the lid and the can into the required seal. Low pressure in the air system driving the seam rollers or an inadequate dwell time in the seaming process lead to discontinuity in the seam area. This causes dimensional variations in the seam area. Additionally, if the seam producing rollers travel too far into the seam forming area or not far enough, an inadequate seam is formed. These inaccuracies frequently lead to leakage and contamination of contents within the can. Such cans are not acceptable for further processing or sale, which leads to inefficiencies in the canning process and production of canned foods and beverages.
The repeatable seam apparatus disclosed herein is intended to overcome one or more of the problems discussed above.